SMSL M500 DAC Only “Thermal Issue” not “Golden Sample”

[TC!!]

Found another evidence that 9038pro needs a heatsink. Check out this post about W4S Dac2SE: https://audiophilestyle.com/forums/...-unequivocally/?do=findComment&comment=639206

Excerpt from the post: "The heat issue was interesting to find. The ESS data sheet states that the 9038 is a pin-compatible replacement for the 9018, and the exposed pad on the 9038 ”can be left open, connected to digital or analog ground. Internally connected to substrate via a conductive epoxy”, to quote ESS. Our 9038 chip implementation operated completely within acceptable temperature range, however, we found that once it reached a certain temperature after playing consecutive DSD tracks the sound would develop artifacts reminiscent of a noisy transistor. Adding to this, we found that the provided specs noted a MCLK far less than what is required for higher rate playback such as DSD256. With higher rates comes higher current demand and with that comes heat.

Our solution was a custom heatsink, made in-house with our CNC machine. See the images below. You can see how large the heatsink is, this was purposefully made to ensure proper cooling within a chassis that doesn’t have much moving air. Natural convection cooling is not very efficient so the heatsink disperses it over a large area. Together, with a more efficient 5v regulator we are now using, the result is a much cooler running product that is actually cooler than the previous DAC-2 DSDse!

We’re quite pleased with the results and our solution as the heatsink not only solves the immediate problem, but actually ensures unit performance in the long run as well. I can report that after 3 days of thermal testing, we are able to keep the chip under 45c in an 26c room playing nothing but the highest rate for maximum heat. Given the chip is tolerant up to 75c, we’re in great shape.

Once the updates were implemented, all reported issues were resolved and playback was flawless. I know this because I’ve been personally listening to each unit for 30 minutes before they ship. This new DAC is unbelievably engaging!"

So that does go along with my idea that heat is relative to the 'load' on the main DAC chip just like the load of a microprocessor. Conversely leaving it on over night with no signal may not be an issue.

The holes for a heatsink on the design are very interesting. The heatsink in the post was massive. Wonder if we could bolt something on which attaches to the main case and use that as a huge heatsink. Could use it to keep my coffee warm

 

[Alerma]

If missing heatsink is an issue, SMSL at least may come up with an option to get their 'aftermarket' heatsink for M500 and install it in-house. Many of us should have enough skills to do it...

 

[maxxevv]

This internals image shows that there are mount holes for a heatsink but it is not installed, so it is not the board design issue, but probably SMSL is trying to save on a heatsink?

The heatsink in the article link is way big, and not very effective due to its design. Just get a cheap copper heatsink that's about 4x the chip's size, and maybe 1/2 inch tall with the requisite fins, designed for use with computer chips.

It will work way better than what the article guys did. and way cheap to boot.

 

[Alerma]

Gustard DAC X26 (dual 9038pro) also uses a heatsink per ess chip.

 

[MusicNBeer]

I wonder if Amir's prototype has a heatsink and the production model does not...

 

[VeerK]

I’m curious about the internals of Amir’s unit, the rev 1 that Wolfe measured, and the rev 2 that are now being shipped after the delay from SMSL. I don’t like the fact that this is the second time SMSL/Sabaj has had thermal issues, and the second time an SMSL production model has differences from the review model (SP200 volume pot). Definitely souring here, and strongly considering the Topping D90 after more reviews. Valuable lessons learned here

 

[SoyBean0809]

This internals image shows that there are mount holes for a heatsink but it is not installed, so it is not the board design issue, but probably SMSL is trying to save on a heatsink?

I think the heat sink (if there is any) was simply taken away when taking these photos, so as to reveal the ess chip underneath it. It's hard to imagine that smsl will save on a heatsink. But it will be interesting to see what does it look like inside the production model though.

 

[VeerK]

Over on Facebook, Topping says the dimensions are 22.2x16.0x4.5cm

 

[TC!!]

I wonder if Amir's prototype has a heatsink and the production model does not...

Unless I've missed something @amirm was able to see the effect of temperature when he retested the device after leaving it warm up for a while. That is why people aren't getting angry about Amir being sent a golden sample, he was able to replicate the issue on the one he was sent.

 

[Alerma]

Impatiently looking forward to M500 teardown/(internal inspection) to see if it has a heatsink over ess chip

 

[WolfX-700]

I have a problem with teardown M500.Because it seems that it is impossible to disassemble this unit without peeling off the plastic sheet in front of the display……

Considering my friend's unit, I shouldn't do what might be "irreversible".So please wait until the unit I bought arrives and take some measurements before I disassemble ...

 

[Koeitje]

@SMSL-Mandy might be able to shed some light on this?

 

[Alerma]

I have a problem with teardown M500.Because it seems that it is impossible to disassemble this unit without peeling off the plastic sheet in front of the display……

Considering my friend's unit, I shouldn't do what might be "irreversible".So please wait until the unit I bought arrives and take some measurements before I disassemble ...

Sure, no problems. However I wouldn't expect to see any screws behind the plastic sheet in front of the display. It would be too difficult/expensive process for SMSL to assemble units this way. I guess everything should slide out from behind once you unscrewed 4 screws in back/2 screws in front of the unit. Just guessing...

Edit: the knob should be removed too, of course

 

[WolfX-700]

Sure, no problems. However I wouldn't expect to see any screws behind the plastic sheet in front of the display. It would be too difficult/expensive process for SMSL to assemble units this way. I guess everything should slide out from behind once you unscrewed 4 screws in back/2 screws in front of the unit. Just guessing...

I tried the way you said ...

I even removed all the screws on the back panel ...

No way

I guess the plastic board in front of the monitor is directly attached with double-sided tape, so it is easy to produce

 

[mkawa]

@SMSL_Liu or @SMSL-Mandy, could you please provide production unit PCB photos (with heatsinks if they are present on the production units) and save @WolfX-700 some trouble? even better, a teardown video from the smsl lab?

given that you've made some pcb photos available, i assume this isn't that significant a request?

i ask because smsl has been very transparent about production and measurements, and it has gone a long way towards reassuring those who are on the fence about purchasing.

 

[Alerma]

@SMSL_Liu or @SMSL-Mandy, I am supporting the request too. Maybe we should create a petition to SMSL for that matter?

 

[mkawa]

why don't we give smsl more than 17 minutes to respond

 

[WolfX-700]

@SMSL_Liu or @SMSL-Mandy, I am supporting the request too. Maybe we should create a petition to SMSL for that matter?

Actually I didn't want to say ...

But seeing that you have been calling the official staff of SMSL ...

I have to say that I actually joined the SMSL consumer contact group.

Not only did the official have no response to this post, there was even a little deliberate disregard or even ridicule.

 

[mkawa]

that, that is not good. pending some more data, i may well be returning my unit for a topping design.

 

[WolfX-700]

that, that is not good. pending some more data, i may well be returning my unit for a topping design.

As everyone knows, SMSL is a Chinese manufacturer-in fact, communication should have been very easy.

I have previously consulted about the volume imbalance of the SP200, including suggestions: Will you consider replacing a better potentiometer?

The answer is cold: we will not consider replacing the potentiometer model. If you feel that it is not balanced, return it for another.

It's hard to say what's wrong with this response ... it just feels bad.